Image-transformer for distance photography.



C. STlL-LE.

IMAGE TRANSFORMER FOR DISTANCE PHOTOGRAPHY.

APPLICATION FILED APR. 2% I913.

' 1,141,850, Patented June 1, 1915.-

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" UNITED STATES PATENT OFFI E-j CURT STILLE, OF ZEHLENDORE-WEST, BERLIN, GERMANY.

To all whom it may concern: L

Be it known that I, Cnn'r S'rmnn, doctor ofphilosophy, of Zehlendorf-West, Ger-' many, a subject of the King of Prussia, and whose post-office address is 4/5B1'ilowstrasse.- ZehIendorf West, near Berlin, Kingdom of- Prussia, German Empire, have invented a new and useful Image-Transformer for Distant' Photography, of which the following is a specification.

, It has been proposed to employ electrooptical polarization phenomena for the purpose of converting back into light-images electric currents, whose variations correspond to the local intensities of light of an object divided into sections fromwhich object the currents are emitted or generated. To this end, a ray of light, polarizedby means of Nicols prisms, is led through a taneously by strong direct current and weak.

column of bisulfid of carbon and the like electro-optically sensitive -substances, whereby the said column is placed in an electromagnetic field, whose intensity depends upon the variations of the lightecurrents. It has, however, been found in practice that the phenomena are much more intense when strong fields of lines of force are employed in such a' mann r, as to excite the field simulalternating current, so that the fields overlie each other.

rents, that is to say, currents whose inten- The achievement of this object forms the subject of the present invention.

The invention isv illustrated diagrammatically in the accompanying drawing- The core 'A is magnetized by the coil 0. In this coil flow the so-called light cursitv corresponds to the different degrees of brightness of the different parts of the object. The momentary magnetism of the core corresponds therefore to the momentaryflntensity of the light current. The core .has

a further winding G in which currents are induced. The induced currents are transmitted by a relay R having a contact K to a local current circuit. In, addition tov the contact K,-this current circuit contains a battery B and a winding W constituting the primary of a transformer T, of which the secondary is marked S. In the-circuit vof the secondary there is included a source of strong current (direct current) D, the sec ondary S, and a polarizer P. The latter IMAGE-TRANS4FORMEB FOR DISTANCE PHOTOGRAPH Y.

Specification of Letters Patent. Patented J 1 113 1, 1915 Application filed, April 22, 1913. Serial No. 762,925.

which is placed a polarizing tube Q with two Nlcols prisms N. The purpose of this arrangement is to workwith superposed or overlying fields instead of using the fields WhlCh are produced either directly by'the light currents, or indirectly by these in substance. sensitive to light (silver bromid gelatin) which passes through under the polarizing apparatus isexposed correspondingly to the current variations. The passage of the sensitized Strip past the polarizing apparatus takes place in the same manner as the image (which is transmitted to a distance) passes in front of the lightsensitive' cell at the transmitting station.

Thus an intermittent sub-division. and reconstitution of the image are effected bv well known means at the transmitting and receiving stations respectively.

What I do claim as my invention, and desire to secure by Letters Patent of the United States, is

1. The process of converting light rays consisting in generating alternating current impulses in accordance with the light intensities of an object; impressing said impulses upon a direct current; and then subjecting polarized light rays to the influence of the resultant field of electric force.

2. The process of converting light rays consisting in polarizing the light rays; and subjecting .the polarized light to the influence of simultaneous strong direct and'weak alternating electric currents.

3. An apparatus for converting light rays comprising an electro-optical polarizing device; and means for producing simultaneously direct and alternating currents within said device.

- 4. An apparatus for converting light rays comprising an electro-optical polarizingdevice; and means for generating a magnetic field in the polari-zer by a primary direct current'and a secondary alternating current.

' 5-. .An' apparatus for converting light rays comprising a local direct current circuit; an electro-optical polarizing device in said circuit; and an alternating current circuit adapted to carry electric current impulses dependent upon the variation of light in cuit; an alternating current circuit adapted to carry current impulses dependent upon I the variation of light intensity of the object;

' and an interrupter and transformer associated with said circuits to produce simultafneously strong direct and Weak alternating currents in the polarizing device of the local .circuit.

In testimony whereof I have hereunto set my hand in presence of two subscribing Wit 1t nesses.

' OURT STILLE.

.Witnesses:

WALDEMAR GHBIBKENNY,

HANS Tnoem. 

